JP2021169901A - Storage water heater - Google Patents

Abstract

To provide a storage water heater advantageous in both easily using hot water in a hot water storage tank during water supply shutdown and suppressing manufacturing cost.SOLUTION: A storage water heater 35 includes: outgoing piping serving as a water passage leading from a hot water storage tank 8 to an HP unit 7; return piping having a downstream end connected to the other end 21a of tank upper piping 21; a circulation pump 12 causing water in the outgoing piping and the return piping to flow; and four-way valve 18 enabling switching between a first path in which the water flowing in the outgoing piping flows through the HP unit 7 to the return piping and a second path in which the water flowing in the outgoing piping flows through bypass piping to the return piping without passing through the HP unit 7. When a water supply shutdown mode is set, a control section 36 supplies hot water in the hot water storage tank 8 to a faucet 90 side by performing a water supply shutdown mode operation for operating the circulation pump 12 while the four-way valve 18 is set to the second path state.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a hot water storage type water heater.

Patent Document 1 below discloses a heater-type hot water storage type water heater provided with a pump that conveys hot water in a hot water storage tank to a hot water outlet pipe when water is cut off.

Japanese Unexamined Patent Publication No. 2014-178804

The hot water storage type water heater of Patent Document 1 is a heater type water heater, and normally does not use a pump. In the technique of Patent Document 1, it is necessary to install a pump that is not used except in an emergency such as when water is cut off, so that the manufacturing cost is high.

This disclosure is made to solve the above-mentioned problems, and is an advantageous hot water storage type in order to easily use the hot water in the hot water storage tank when the water is cut off and to suppress the manufacturing cost at the same time. The purpose is to provide a water heater.

The hot water storage type water supply machine according to the present disclosure includes a heating means for heating water, a hot water storage tank for storing hot water heated by the heating means, a water supply pipe for flowing water supplied from a water source into the hot water storage tank, and a hot water side. A mixing valve that mixes the hot water that flows in from the inlet and the water that flows in from the water side inlet, a hot water supply pipe that mixes with the mixing valve and allows hot water to flow toward the faucet side, and one end that communicates with the upper part of the hot water storage tank. Connected to the tank upper pipe having the other end communicating with the hot water side inlet, the outgoing pipe serving as a water channel from the hot water storage tank to the heating means, the upstream end communicating with the water outlet of the heating means, and the other end of the tank upper pipe. A return pipe having a downstream end, a circulation pump for flowing water from the outgoing pipe and the return pipe, a bypass pipe, a first path through which water flowing through the outgoing pipe flows to the return pipe through a heating means, and an outgoing pipe. A route switching means capable of switching between a second path in which water flowing through the pipe flows to the return pipe through the bypass pipe without passing through the heating means, a control unit for controlling the operation of the circulation pump and the operation of the route switching means, and the control unit. The control unit has a water cutoff mode used when the water source is cut off as an operation mode, and when the water cutoff mode is set, the control unit operates the circulation pump with the route switching means as the second path. The hot water in the hot water storage tank is supplied to the faucet side by performing the water cutoff mode operation.

According to the present disclosure, it is possible to provide a hot water storage type water heater which is advantageous in achieving both easy use of hot water in a hot water storage tank and reduction of manufacturing cost when water is cut off.

It is a figure which shows the hot water storage type water heater according to Embodiment 1. FIG. It is a figure which shows the flow of hot water at the time of the water cutoff mode operation of the hot water storage type water heater shown in FIG. It is a flowchart which shows the control process at the time of the water cutoff mode of the hot water storage type water heater by Embodiment 1.

Hereinafter, embodiments will be described with reference to the drawings. The same reference numerals are given to common or corresponding elements in each figure to simplify or omit the description. In the following description, the description of "water" or "hot water" means, in principle, liquid water, and may include low-temperature water to high-temperature water.

Embodiment 1.
FIG. 1 is a diagram showing a hot water storage type water heater 35 according to the first embodiment. The hot water storage type water heater 35 includes a water circuit through which hot water flows. The hot water storage type water heater 35 of the first embodiment includes a tank unit 33 and an HP unit 7. The HP unit 7 and the tank unit 33 are connected to each other via an HP going pipe 14, an HP returning pipe 15, and an electric wiring (not shown). The tank unit 33 has a built-in control unit 36. The operation of various valves, pumps, etc. included in the tank unit 33 and the HP unit 7 is controlled by a control unit 36 electrically connected to these. The control unit 36 includes, for example, a microcomputer having at least one memory and at least one processor. The control unit 36 corresponds to a control means for controlling the operation of the hot water storage type water heater 35. The control unit 36 may have a timer function for managing the date and time. It should be noted that the configuration is not limited to the configuration in which the operation is controlled by a single control unit 36 as shown in the drawing, and the operation may be controlled by the cooperation of a plurality of control devices.

The remote controller 44 has a function of receiving a user instruction regarding a driving operation command and a change of a set value. The remote controller 44 is an example of a user interface. The control unit 36 and the remote controller 44 are connected by wire or wireless so that data communication is possible in both directions. Although not shown, the remote controller 44 is equipped with a display unit that displays information such as the status of the hot water storage type water heater 35, an operation unit such as a switch operated by the user, a speaker, a microphone, and the like. The display unit of the remote controller 44 has a function as a notification means for notifying the user of information. The remote controller 44 in the present embodiment includes a display unit as a notification means, but as a modification, other notification means such as a voice guidance device may be provided.

In the present embodiment, the remote controller 44 may be installed on a wall such as a kitchen, a living room, or a bathroom. A plurality of remote controllers 44 may be able to communicate with the control unit 36. It may be configured so that other user interfaces, such as smartphones or smart speakers, can be used in place of or in addition to the remote control 44. The user interface and the control unit 36 may communicate with each other via a home network or the Internet.

The HP unit 7 is an example of a heating means for heating water. The HP unit 7 includes a refrigerant circuit in which a compressor 1, a water refrigerant heat exchanger 3, an expansion valve 4, and an air heat exchanger 6 are cyclically connected by a refrigerant pipe 5. The HP unit 7 operates the heat pump cycle by this refrigerant circuit. In the water refrigerant heat exchanger 3, water is heated by exchanging heat between the refrigerant compressed by the compressor 1 and the water guided from the tank unit 33.

The heating means in the present disclosure is not limited to a heat pump such as the HP unit 7. The heating means in the present disclosure may be, for example, one that heats water by utilizing at least one of a gas engine, geothermal heat, solar heat, and waste heat of a fuel cell.

The tank unit 33 contains the following various parts and pipes. The hot water storage tank 8 stores hot water. Inside the hot water storage tank 8, a temperature stratification can be formed in which the upper side is high temperature and the lower side is low temperature due to the difference in water density depending on the temperature.

The hot water storage tank 8 includes an upper part, an intermediate part, and a lower part. The middle portion of the hot water storage tank 8 is a height portion between the upper portion of the hot water storage tank 8 and the lower portion of the hot water storage tank 8. The hot water storage tank 8 is not limited to a single tank as shown in the figure, and may include a plurality of tanks connected in series. In the present disclosure, regarding the description of the position of the hot water storage tank 8 in the height direction, that is, in the vertical direction, when the hot water storage tank 8 includes a plurality of tanks connected in series, the highest tank to the lowest tank 8 are provided. The vertical position shall be specified in the entire hierarchy up to the tank.

At the lower part of the hot water storage tank 8, a tank lower port 8a, a water outlet 8b, and a water introduction port 8c are provided. A hot water introduction outlet 8d is provided above the hot water storage tank 8. In the illustrated example, the water inlet 8c is located higher than the tank lower port 8a and the water outlet 8b.

A third water supply pipe 9c is connected to the tank lower port 8a. The water supplied from a water source such as a water supply through the first water supply pipe 9a is decompressed to a predetermined pressure by the pressure reducing valve 31, and then flows into the hot water storage tank 8 through the third water supply pipe 9c. On the surface of the hot water storage tank 8, a plurality of hot water storage temperature sensors 42 and 43 are attached at positions at different heights from each other. Not limited to the illustrated example, three or more hot water storage temperature sensors may be provided in the hot water storage tank 8. The control unit 36 can detect the amount of remaining hot water in the hot water storage tank 8 by detecting the temperature distribution of the hot water in the hot water storage tank 8 with these hot water storage temperature sensors 42 and 43. The "remaining hot water amount" in the present disclosure corresponds to the heat storage amount in the hot water storage tank 8.

The tank unit 33 contains a bath heat exchanger 60 and a bath circulation pump 29. The bath heat exchanger 60 has a primary side flow path 60a and a secondary side flow path 60b. The bath heat exchanger 60 corresponds to a heat exchanger that exchanges heat between the primary fluid flowing through the primary side flow path 60a and the secondary fluid flowing through the secondary side flow path 60b. In the present embodiment, an example in which bath water circulating from the bath tub 30 flows through the secondary side flow path 60b as a secondary fluid will be described. Instead of this example, the secondary fluid in the present disclosure may be a fluid other than bath water. For example, the secondary fluid may be a heat medium for heating or water supplied from a water source.

The bath going pipe 27 connects the outlet of the secondary side flow path 60b and the bathtub 30. A bath going temperature sensor 37 for detecting the temperature of the bath water flowing out from the bath heat exchanger 60 is installed in the middle of the bath going pipe 27. The bath return pipe 28 connects the inlet of the secondary side flow path 60b and the bathtub 30. In the middle of the bath return pipe 28, a bath circulation pump 29 for circulating bath water in the secondary side flow path 60b and a bath return temperature sensor 38 for detecting the temperature of the bath water discharged from the bathtub 30 are provided. It is provided.

The tank unit 33 further includes a three-way valve 11, a circulation pump 12, a four-way valve 18, a hot water supply mixing valve 22, and a bath mixing valve 23. Each of the three-way valve 11 and the four-way valve 18 corresponds to a route switching means capable of switching the route through which hot water flows.

The three-way valve 11 has an a port and a b port as an inlet and a c port as an outlet. The three-way valve 11 is configured so that the flow path can be switched between the two paths ac and bc. The four-way valve 18 has an inlet b port and a c port, and an outlet a port and a d port. The four-way valve 18 is configured so that the flow path can be switched between the four paths of ab, ac, bd, and cd.

Each of the hot water supply mixing valve 22 and the bath mixing valve 23 has a hot water side inlet and a water side inlet, and adjusts the hot water supply temperature by mixing the hot water flowing in from the hot water side inlet and the water flowing in from the water side inlet. do. One end of the first water supply pipe 9a is connected to a water source such as a water supply. The second water supply pipe 9b and the third water supply pipe 9c are connected to the other end of the first water supply pipe 9a via the pressure reducing valve 31. The second water supply pipe 9b is connected to each water side inlet of the hot water supply mixing valve 22 and the bath mixing valve 23.

The low temperature pipe 10 connects the water outlet 8b and the a port of the three-way valve 11. The HP going pipe 14 connects the c port of the three-way valve 11 and the water inlet of the water refrigerant heat exchanger 3. A circulation pump 12 is connected in the middle of the HP going pipe 14. The HP return pipe 15 has an upstream end communicating with the water outlet of the water refrigerant heat exchanger 3 and a downstream end connected to the c port of the four-way valve 18. The first bypass pipe 16 connects the a port of the four-way valve 18 and the water introduction port 8c. The second bypass pipe 17 connects the branch portion 54 provided in the HP going pipe 14 between the circulation pump 12 and the water refrigerant heat exchanger 3 and the b port of the four-way valve 18.

One end of the tank upper pipe 21 is connected to the hot water introduction outlet 8d. The other end 21a of the tank upper pipe 21 communicates with the hot water side inlets of the hot water supply mixing valve 22 and the bath mixing valve 23 via the hot water side pipe 50. The hot water supply pipe 13 has an upstream end connected to the d port of the four-way valve 18 and a downstream end connected to the other end 21a of the tank upper pipe 21. The pipe 20a connects the upper part of the hot water storage tank 8 and the inlet of the primary side flow path 60a. The pipe 20b connects the outlet of the primary side flow path 60a and the b port of the three-way valve 11.

The hot water supply mixing valve 22 adjusts the flow rate ratio of the high temperature water supplied from the hot water storage tank 8 through the tank upper pipe 21 and the hot water side pipe 50 to the low temperature water supplied from the second water supply pipe 9b. , The user generates hot water having a set temperature set by the remote controller 44 and flows it into the hot water supply pipe 24. Hot water mixed by the hot water mixing valve 22 and heading toward the faucet 90 passes through the hot water supply pipe 24. The downstream end of the hot water supply pipe 24 is connected to the hot water supply plug 34. For example, a faucet 90 such as a shower or a curan provided in a house and a hot water tap 34 are connected by an external hot water supply pipe 91 arranged outside the hot water storage type water heater 35. When the user opens the faucet 90, the hot water flowing into the hot water supply pipe 24 from the hot water supply mixing valve 22 is supplied to the faucet 90 through the hot water supply plug 34 and the external hot water supply pipe 91. The flow rate of water flowing through the hot water supply pipe 24 is hereinafter referred to as "hot water supply flow rate". A hot water supply flow rate sensor 52 that detects the hot water supply flow rate is installed in the hot water supply pipe 24.

The bath mixing valve 23 adjusts the flow rate ratio of the high temperature water supplied from the hot water storage tank 8 through the tank upper pipe 21 and the hot water side pipe 50 to the low temperature water supplied from the second water supply pipe 9b. , The user generates hot water having a set temperature set by the remote controller 44 and flows it into the bath pipe 25. The hot water that has flowed into the bath pipe 25 from the bath mixing valve 23 flows into the bathtub 30 via the bath flow sensor 45, the bath solenoid valve 26, the bath going pipe 27, and the bath returning pipe 28.

A relief valve 32 with a negative pressure actuating valve is connected to a branch pipe 39 branched from the middle of the tank upper pipe 21. The relief valve 32 with a negative pressure operating valve opens and performs a pressure relief operation when the pressure in the hot water storage tank 8 exceeds a predetermined set pressure. That is, the relief valve 32 with a negative pressure operating valve has a function as a relief valve for releasing the pressure in the hot water storage tank 8. When the pressure inside the hot water storage tank 8 rises and exceeds the set pressure during hot water storage operation, the relief valve 32 with a negative pressure operating valve opens and the hot water is discharged to the outside of the system, so that the pressure rise inside the hot water storage tank 8 is suppressed. Will be done. The relief valve 32 with a negative pressure operating valve in the present embodiment also has a function of performing a negative pressure operation that opens when the inside of the hot water storage tank 8 becomes negative pressure to allow external air to flow into the hot water storage tank 8. The relief valve 32 with a negative pressure actuating valve is arranged at a position higher than that of the hot water supply mixing valve 22.

In the present embodiment, the HP going pipe 14 corresponds to a "going pipe" which is a water channel from the hot water storage tank 8 to the HP unit 7. The HP return pipe 15 and the hot water supply pipe 13 correspond to a “return pipe” that serves as a water channel from the HP unit 7 to the hot water storage tank 8. The four-way valve 18 has a "first path" in which water flowing through the HP outgoing pipe 14 flows through the HP unit 7 to the HP return pipe 15 and the hot water supply pipe 13, and water flowing through the HP outgoing pipe 14 passes through the HP unit 7. It corresponds to a route switching means capable of switching between the "second route" flowing to the hot water supply pipe 13 through the second bypass pipe 17 without using the second bypass pipe 17.

The hot water storage type water heater 35 can execute the hot water storage operation. The hot water storage operation is an operation in which hot water heated by the HP unit 7, that is, high-temperature water is made to flow into the hot water storage tank 8 and stored. The control unit 36 controls the start and stop of the hot water storage operation according to the amount of remaining hot water in the hot water storage tank 8. The control unit 36 controls the operation of the hot water storage operation as follows. The three-way valve 11 communicates between the a and c ports. The four-way valve 18 is used as the first path, and the cd ports communicate with each other. The HP unit 7 and the circulation pump 12 are operated, and the low-temperature water at the lower part in the hot water storage tank 8 passes through the water outlet 8b, the low-temperature pipe 10, the three-way valve 11, the circulation pump 12 and the HP outbound pipe 14, and exchanges heat with the water refrigerant. It flows into the vessel 3. For example, high temperature water of 65 ° C. generated by heating this low temperature water in the water refrigerant heat exchanger 3 passes through the HP return pipe 15, the four-way valve 18, the hot water supply pipe 13, and the tank upper pipe 21. It flows into the hot water storage tank 8 from the hot water introduction outlet 8d. When the hot water storage operation is executed, high-temperature water is stored from the upper part to the lower part of the hot water storage tank 8, and the layer of the high-temperature water gradually becomes thicker. When the amount of heat stored in the hot water storage tank 8 detected by the hot water storage temperature sensors 42 and 43 exceeds a predetermined amount, the control unit 36 ends the hot water storage operation.

Immediately after the HP unit 7 is started, the temperature of the hot water flowing out of the HP unit 7 does not rise sufficiently. Therefore, immediately after the HP unit 7 is started, the control unit 36 communicates between the a-c ports of the four-way valve 18 and allows the hot water flowing out of the HP unit 7 to pass through the first bypass pipe 16 to the hot water storage tank 8. It may flow into the lower part.

In the following description, the state in which the water from the water source supplied to the first water supply pipe 9a is not supplied to the hot water storage type water heater 35 is referred to as a "water cutoff state", and the state in which water is supplied from the water source to the first water supply pipe 9a is referred to as "water supply pipe 9a". It is called "normal water supply state". The control unit 36 controls the operation of the hot water supply operation in the normal water supply state as follows. When the user opens the faucet 90, the hot water in the hot water storage tank 8 is transferred to the tank upper pipe 21 and the hot water side due to the pressure supplied from the water source through the first water supply pipe 9a and the third water supply pipe 9c into the hot water storage tank 8. It passes through the pipe 50 and flows into the hot water side inlet of the hot water supply mixing valve 22. Further, water from the water source passes through the first water supply pipe 9a and the second water supply pipe 9b and flows into the water side inlet of the hot water supply mixing valve 22. The hot water mixed by the hot water supply mixing valve 22 is supplied to the faucet 90 through the hot water supply pipe 24, the hot water supply plug 34, and the external hot water supply pipe 91.

The control unit 36 has a water cutoff mode used when the water is cut off as an operation mode. When the water cutoff mode is set, the control unit 36 supplies the hot water in the hot water storage tank 8 to the faucet 90 side by performing the water cutoff mode operation in which the circulation pump 12 is operated with the four-way valve 18 as the second path. can do.

FIG. 2 is a diagram showing the flow of hot water when the hot water storage type water heater 35 shown in FIG. 1 is operated in the water cutoff mode. In the water cutoff mode operation, it becomes as follows. The three-way valve 11 is in a state where the a-c ports communicate with each other. The four-way valve 18 is in a state of a second path in which the b-d ports communicate with each other. The circulation pump 12 is operated. When the user opens the faucet 90, the hot water flowing out from the water outlet 8b of the hot water storage tank 8 is sent to the low temperature pipe 10, the three-way valve 11, the HP going pipe 14, the circulation pump 12, the second bypass pipe 17, the four-way valve 18, and the water. It is supplied to the faucet 90 through the hot water pipe 13, the hot water side pipe 50, the hot water supply mixing valve 22, the hot water supply pipe 24, the hot water supply plug 34, and the external hot water supply pipe 91. This route is hereinafter referred to as a "water supply route at the time of water outage". According to the water cutoff mode operation, the user can take out the hot water in the hot water storage tank 8 from the faucet 90 in the house and use it when the water is cut off. At this time, since the user does not have to go to the location of the tank unit 33, the hot water in the hot water storage tank 8 can be easily used.

When the hot water in the hot water storage tank 8 is supplied to the faucet 90 in the water cut state, the inside of the hot water storage tank 8 becomes negative pressure, the relief valve 32 with the negative pressure operating valve opens, and the outside air enters the hot water storage tank 8. Inflow to.

According to this embodiment, in the event of an emergency water outage, the user can take in the hot water in the hot water storage tank 8 from the faucet 90 that is normally used, which is excellent convenience. Is obtained. Further, since the circulation pump 12 used for the hot water storage operation can be used as a water supply pump when the water is cut off, it is not necessary to add a pump and the manufacturing cost does not increase.

In the present embodiment, the tank upper pipe 21 and the branch pipe 39 are not included in the water supply path at the time of water outage. That is, the relief valve 32 with the negative pressure actuating valve is connected to the hot water storage tank 8 via a path different from the water supply path at the time of water outage. As a result, it is possible to more reliably prevent hot water from flowing to the relief valve 32 with the negative pressure operating valve during the water cutoff mode operation. Therefore, it is possible to more reliably prevent hot water from being discharged from the relief valve 32 with a negative pressure actuating valve or obstructing the intake of outside air from the relief valve 32 with a negative pressure actuating valve during operation in the water cutoff mode. ..

FIG. 3 is a flowchart showing a control process in the water cutoff mode of the hot water storage type water heater 35 according to the first embodiment. The remote control 44 or other user interface is configured to allow the user to select and set a water outage mode. When it is desired to take out the hot water in the hot water storage tank 8 from the faucet 90 when the water is cut off, the user can select and set the water cutoff mode using the user interface. In step S1 of FIG. 3, the control unit 36 determines whether or not the user has set the water cutoff mode by the user interface. When the water cutoff mode is set, the process proceeds to step S2, and the control unit 36 sets the drive time of the circulation pump 12 in the water cutoff mode operation. This set drive time is hereinafter referred to as "set drive time". The set drive time corresponds to the upper limit of the integrated operation time of the circulation pump 12 in one water cutoff mode operation. In the present embodiment, by providing the set drive time, it is possible to reliably prevent the circulation pump 12 from being driven for an unnecessarily long time in the water cutoff mode operation.

From step S2 to step S3, the control unit 36 changes the opening degree of the four-way valve 18 and the opening degree of the three-way valve 11 as necessary. That is, the four-way valve 18 is in a state of a second path in which the b-d ports communicate with each other, and the three-way valve 11 is in a state of communicating between the a-c ports.

From step S3 to step S4, the control unit 36 controls the hot water supply mixing valve 22 so that the opening degree of the hot water supply mixing valve 22 becomes 1050 steps, which is the opening degree at which the hot water side inlet is fully opened.

From step S4 to step S5, the control unit 36 drives the circulation pump 12 so that the circulation pump 12 rotates at a predetermined rotation speed (for example, 3500 rpm). As a result, hot water flows through the water supply path when the water is cut off, and water can be taken from the faucet 90. In the present embodiment, the process of step S4 widens the opening area when the hot water from the hot water storage tank 8 enters the hot water supply mixing valve 22, and reduces the pressure loss. As a result, it is possible to increase the flow rate of hot water that can be taken from the faucet 90.

The value of the predetermined rotation speed is set in advance according to the pressure loss of the water supply path when the water is cut off. When the faucet 90 is closed while the circulation pump 12 is being driven in the water cutoff mode operation, the pressure in the hot water storage tank 8 is higher than when the faucet 90 is open. The value of the predetermined rotation speed is set so that the pressure in the hot water storage tank 8 at this time becomes lower than the set pressure at which the relief valve 32 with the negative pressure operating valve opens. That is, in the water cutoff mode operation, the control unit 36 sets the circulation pump 12 so that the rotation speed of the circulation pump 12 is lower than the rotation speed when the relief valve 32 with the negative pressure operating valve operates to release the pressure. Activate. As a result, it is possible to reliably prevent the relief valve 32 with the negative pressure operating valve from opening and the hot water from being discharged to the outside of the system during the water cutoff mode operation.

Further, the value of the predetermined rotation speed is set so that the hot water of the hot water supply pipe 13 does not flow into the tank upper pipe 21 when the hot water flows through the water supply path when the water is cut off. As a result, it is possible to reliably prevent hot water from flowing to the relief valve 32 with the negative pressure actuating valve through the tank upper pipe 21 and the branch pipe 39. Therefore, when the inside of the hot water storage tank 8 becomes negative pressure, the relief valve 32 with the negative pressure operating valve is surely operated by the negative pressure to open, so that the outside air can surely flow into the hot water storage tank 8. ..

During the execution of the water cutoff mode operation, the control unit 36 measures the integrated operation time of the circulation pump 12. From step S5 to step S6, the control unit 36 determines whether or not the current integrated operation time has reached the set drive time. If the integrated operation time has not yet reached the set drive time, the control unit 36 continues the operation of the circulation pump 12 and repeats the process of step S6. When the integrated operation time reaches the set drive time, the process proceeds from step S6 to step S7, and the control unit 36 stops the circulation pump 12 and ends the water cutoff mode.

In the present embodiment, the control unit 36 stops the circulation pump 12 when the integrated operation time reaches the set drive time, so that the circulation pump 12 operates even after the hot water in the hot water storage tank 8 is used up. Since it is possible to reliably prevent the continuation, it is possible to suppress power consumption and more reliably prevent the circulation pump 12 from failing.

If the hot water supply flow rate of the hot water supply pipe 24 becomes lower than the standard during the execution of the water cutoff mode operation, the control unit 36 determines that the user has finished taking water from the faucet 90 or has used up the hot water in the hot water storage tank 8. The circulation pump 12 may be stopped. As a result, it is possible to more reliably prevent the circulation pump 12 from being driven unnecessarily. At this time, the control unit 36 waits for a predetermined time (for example, 10 minutes) that the hot water supply flow rate sensor 52 does not detect the water flow in the hot water supply pipe 24 during the execution of the water cutoff mode operation, and then causes the circulation pump 12 to operate. You may stop it.

During the execution of the water cutoff mode operation, the control unit 36 detects the temperature of the hot water passing through the hot water supply pipe 24 by the hot water supply temperature sensor 46, and alerts information when the temperature becomes higher than the reference (for example, 50 ° C.). May be notified by the notification means. For example, the announcement of high temperature caution may be displayed as alert information on the display unit of the remote controller 44. In the water cutoff mode operation, the hot water in the hot water storage tank 8 flows to the faucet 90 as it is without being mixed with the low temperature water from the second water supply pipe 9b when passing through the hot water supply mixing valve 22. Therefore, the high temperature water in the hot water storage tank 8 may flow out from the faucet 90 as it is. At that time, by notifying the attention alert information, the user's attention can be surely alerted.

During execution of the water outage mode operation, the remote controller 44 or other user interface may be prohibited from accepting a user instruction other than the user instruction to stop the water outage mode operation. For example, during the execution of the water cutoff mode operation, the user interface may not accept the user instruction for performing the hot water filling operation for storing hot water in the bathtub 30 or the user instruction for performing the hot water storage operation. As a result, it is possible to reliably prevent the hot water filling operation from being executed when the water is cut off and the high temperature water in the hot water storage tank 8 flowing into the bathtub 30 as it is. Further, when the water supply is cut off, the hot water storage operation is executed and the high temperature water in the hot water storage tank 8 flows into the HP unit 7, and the HP unit 7 can reliably prevent the HP unit 7 from detecting the high temperature water entry and stopping abnormally.

In the following description, the temperature difference between the upper water temperature in the hot water storage tank 8 detected by the hot water storage temperature sensor 42 and the lower water temperature in the hot water storage tank 8 detected by the hot water storage temperature sensor 43 is referred to as “the temperature difference in the tank”. It is called. The hot water storage temperature sensors 42 and 43 correspond to the temperature difference detecting means. When the temperature difference in the tank when the water cutoff mode is set is larger than the reference, the control unit 36 may execute the water cutoff mode operation after executing the stirring operation for stirring the hot water in the hot water storage tank 8. good. As a result, the temperature of the hot water in the hot water storage tank 8 can be made uniform and then the water can be supplied to the faucet 90. Therefore, it is possible to surely prevent the temperature of the hot water flowing out from the faucet 90 from being too low or too high, and the convenience is improved. do. During the stirring operation, the control unit 36 notifies the user by using the remote controller 44 or the like so as not to take water from the faucet 90 yet, and controls the three-way valve 11 and the four-way valve 18 to the same opening degree as in the water cutoff mode operation. After that, the circulation pump 12 may be driven at the maximum rotation speed. As a result, the low-temperature water flowing out from the water outlet 8b of the hot water storage tank 8 is discharged from the low-temperature pipe 10, the three-way valve 11, the HP going pipe 14, the circulation pump 12, the second bypass pipe 17, the four-way valve 18, and the hot water supply pipe 13. It flows into the upper part of the hot water storage tank 8 through the tank upper pipe 21 and the hot water introduction outlet 8d. As a result, the low temperature water and the high temperature water in the hot water storage tank 8 are mixed and the temperature is made uniform. After continuing the stirring operation for a predetermined time (for example, 10 minutes), the control unit 36 shifts to the water cutoff mode operation and notifies the user that water can be taken from the faucet 90 by using the remote controller 44 or the like. The stirring operation is not limited to the above method, and may be any operation as long as the inside of the hot water storage tank 8 can be stirred. For example, in the stirring operation, the inside of the hot water storage tank 8 may be agitated by rotating a propeller (not shown) installed in the hot water storage tank 8.

When the amount of remaining hot water in the hot water storage tank 8 when the water cutoff mode is set is smaller than the reference, the control unit 36 may execute the water cutoff mode operation after executing the hot water storage operation. As a result, it is possible to surely prevent the temperature of the hot water flowing out from the faucet 90 from becoming too cold during the water cutoff mode operation, and the convenience is improved. In this case, the control unit 36 may further execute the stirring operation after the hot water storage operation is completed, and then execute the water cutoff mode operation.

1 Compressor, 3 Water refrigerant heat exchanger, 4 Expansion valve, 5 Refrigerator piping, 6 Air heat exchanger, 7 HP unit, 8 Hot water storage tank, 8a Tank lower port, 8b Water outlet, 8c Water inlet, 8d Hot water Introductory outlet, 9a 1st water supply pipe, 9b 2nd water supply pipe, 9c 3rd water supply pipe, 10 low temperature pipe, 11 three-way valve, 12 circulation pump, 13 hot water supply pipe, 14 HP going pipe, 15 HP return pipe, 16th 1 Bypass piping, 17 2nd bypass piping, 18 4-way valve, 20a piping, 20b piping, 21 Tank upper piping, 22 Hot water supply mixing valve, 23 Bath mixing valve, 24 Hot water supply piping, 25 Bath piping, 26 Bath electromagnetic valve , 27 Bath going piping, 28 Bath returning piping, 29 Bath circulation pump, 30 Bathtub, 31 Pressure reducing valve, 32 Relief valve with negative pressure actuating valve, 33 Tank unit, 34 Hot water tap, 35 Hot water storage type water supply machine, 36 Control unit, 37 Bath going temperature sensor, 38 Bath returning temperature sensor, 39 Branch pipe, 42, 43 Hot water storage temperature sensor, 44 Remote control, 45 Bath flow sensor, 46 Hot water temperature sensor, 50 Hot water side piping, 52 Hot water flow sensor, 54 Branch , 60 Bath heat exchanger, 60a primary side flow path, 60b secondary side flow path, 90 faucet, 91 external hot water supply pipe

Claims (10)

A heating means to heat water and
A hot water storage tank for storing hot water heated by the heating means, and
A water supply pipe that allows water supplied from the water source to flow into the hot water storage tank,
A mixing valve that mixes the hot water that has flowed in from the hot water side inlet and the water that has flowed in from the water side inlet.
A hot water supply pipe that is mixed by the mixing valve and allows hot water to pass toward the faucet side.
A tank upper pipe having one end communicating with the upper part of the hot water storage tank and the other end communicating with the hot water side inlet.
An outgoing pipe that serves as a water channel from the hot water storage tank to the heating means,
A return pipe having an upstream end communicating with the water outlet of the heating means and a downstream end connected to the other end of the tank upper pipe.
A circulation pump that allows water to flow through the forward pipe and the return pipe,
Bypass piping and
A first path in which water flowing through the going pipe flows through the heating means to the return pipe, and a second path in which water flowing through the going pipe flows through the bypass pipe to the return pipe without passing through the heating means. A route switching means that can switch between routes and
A control unit that controls the operation of the circulation pump and the operation of the path switching means, and
With
The control unit has a water cutoff mode used when the water source is cut off as an operation mode.
When the water cutoff mode is set, the control unit operates the water cutoff mode in which the circulation pump is operated with the route switching means as the second path, so that the hot water in the hot water storage tank is made into the faucet. A hot water storage type water heater that supplies to the side. A relief valve that opens when the pressure in the hot water storage tank exceeds the set pressure to release the pressure is provided.
The hot water storage according to claim 1, wherein in the water cutoff mode operation, the control unit operates the circulation pump so that the rotation speed of the circulation pump is lower than the rotation speed when the relief valve opens. Type water heater. During the water cutoff mode operation, the hot water in the hot water storage tank passes through the water supply path at the time of water cutoff including the forward pipe, the bypass pipe, the return pipe, the hot water side inlet, the mixing valve, and the hot water supply pipe. Flow to the faucet side,
The hot water storage type water heater according to claim 2, wherein the relief valve is connected to the hot water storage tank via a route different from the water supply route at the time of water outage. The method according to any one of claims 1 to 3, which prohibits the acceptance of user instructions other than the user instruction for stopping the water cutoff mode operation among the user instructions for the user interface during the execution of the water cutoff mode operation. Hot water storage type water heater. The hot water storage type water heater according to any one of claims 1 to 4, wherein in the water cutoff mode operation, the control unit controls the opening degree of the mixing valve so that the hot water side inlet is fully opened. A hot water supply flow rate sensor that detects the flow rate of hot water passing through the hot water supply pipe is provided.
The hot water storage type water heater according to any one of claims 1 to 5, wherein when the flow rate becomes lower than the reference during the execution of the water cutoff mode operation, the control unit stops the circulation pump. A hot water supply temperature sensor that detects the temperature of hot water passing through the hot water supply pipe, and
When the temperature becomes higher than the reference during the execution of the water cutoff mode operation, the notification means for notifying the warning information and the notification means.
The hot water storage type water heater according to any one of claims 1 to 6. A means for detecting the amount of residual hot water in the hot water storage tank is provided.
When the amount of residual hot water when the water cutoff mode is set is smaller than the reference, the control unit executes the hot water storage operation in which the hot water heated by the heating means flows into the hot water storage tank, and then the hot water storage operation is executed. The hot water storage type water heater according to any one of claims 1 to 7, which executes the water cutoff mode operation. A temperature difference detecting means for detecting a temperature difference between the water temperature of the upper part in the hot water storage tank and the water temperature of the lower part in the hot water storage tank is provided.
When the temperature difference when the water cutoff mode is set is larger than the reference, the control unit performs the water cutoff mode operation after executing the stirring operation for stirring the hot water in the hot water storage tank. The hot water storage type water heater according to any one of items 1 to 8. The hot water storage type according to any one of claims 1 to 9, wherein when the integrated operation time of the circulation pump in one water cutoff mode operation reaches the upper limit value, the control unit stops the circulation pump. Water heater.

Images